The field of the disclosure relates generally to passive wireless sensors and, more particularly, to passive wireless sensors for turbomachines.
At least some known turbomachines, i.e., gas turbine engines compress air via a plurality of rotatable compressor blades and ignite a fuel-air mixture in a combustor to generate combustion gases that are channeled through rotatable turbine buckets via a hot gas path. Also, at least some other known turbomachines, i.e., steam turbine engines channel steam through rotatable buckets via a steam path. Such known turbomachines convert thermal energy of the combustion gas stream and steam, respectively, to mechanical energy used to rotate a turbine shaft. Output of the turbomachines may be used to power a machine, for example, an electric generator, a compressor, or a pump.
Many of these known turbomachines include known sensing devices that are configured to withstand high temperatures and the stresses and strains associated with high-velocity rotational effects for only a short period of time, i.e., 100 hours or less. Some of such known sensing devices include measurement instruments coupled to, within a gas turbine, for example, compressor blades and turbine buckets. Such known coupled devises typically require extensive wiring, modifications to the blades and buckets to accommodate the wiring, and complicated slip ring configurations. These features are necessary, due to the rotational operation of the monitored components, to transmit measurement data from the blades and buckets to an external data storage and analysis unit. Therefore, such measurement systems increase construction and maintenance costs.
Other known wireless sensing devices are deposited on blades and buckets through a printing process. Yet other known wireless sensing devices are formed in layers on the surfaces of the rotatable components. Moreover, other known wireless sensing devices are embedded within the rotatable components, e.g., inserted into slots defined within the components during manufacturing. These four methods of coupling, i.e., affixing sensors to the rotatable components require addition of at least some of the sensor components to the rotatable components subsequent to manufacture of such rotatable components. As such, these methods lend themselves to adoption by non-original equipment manufacturers (OEMs). Moreover, post-manufacture affixing of portions of the sensing devices to the rotatable components has a potential for not fully integrating the sensors with the rotatable components. In addition, the most appropriate or desired position on the rotatable components for affixing devices may not be available.